There is a type of applicator called a marker, which is a writing instrument of a reservior-type in which ink, water-based ink, oil-based ink etc., is supplied from an ink occlusion element in the rear barrel to a pen core.
Markers of the reservior type can be classified into various types: for example one type (refer to patent literature 1) in which the content from the ink occlusion element to the pen core can be visually grasped by the user, and one type in which alcohol-based ink is used.
Patent literature 1: Japanese Patent Application Laid-open No. Hei 6-270585.